KA2418B/28 TONE RINGER WITH BRIDGE DIODE
INTRODUCTION
The KA2418B/28 is a monolithic integrated circuit telephone tone
ringer with bridge diode, when coupled with an appropriate
transducer, it replaces the electromechanical bell. This device is
designed for use with either a piezo transducer or an inexpensive
transformer coupled speaker to produce a pleasing tone composed
of a high frequencys (fH1, fH2) alternating with a low frequency (fS)
resulting in a warble frequency. The supply voltage is obtained from
the AC ring signal and the circuit is designed so that noise on the
line or variation of the ringing signal can not affect correct operation
of the device.
FEATURES
• Built-in full wave bridge diode rectifier
• Low current consumption, in order to allow the
parallel operation of the 4 devices
• Few external components
• Tone and adjustable switching frequencies by
external components
• High noise immunity due to built-in voltage to
current hysteresis
• Adjustable activation voltage
• Internal zener diodes to protect against over
voltages
• Adjustable ringer impedance with external
components.
Device Package Operating Temperature
KA2418B
KA2428
• Electronic telephone ringers
• Extension ringers
8-DIP-300
8-DIP-300
- 20°C ~ + 70°C
BLOCK DIAGRAM
RECTIFIER
CAPACITOR
7
8
TIP
-
1
RING
2
GND SWEEP RATE
Fig. 1
POWER
+
SUPPLY
CONTROL
CIRCUIT
3
CONTROL
CAPACITOR
FREQ OSC
LOW
4
OUTPUT FREQUENCY
CONTROL RESISTOR
HIGH
FREQ OSC
ACTIVATION
VOLTAGE ADJUSTABLE
6
OUTPUT
AMP
5
OUTPUT
KA2418B/28 TONE RINGER WITH BRIDGE DIODE
ABSOLUTE MAXIMUM RATINGS
Characteristic Symbol Value Unit
Calling Voltage (f = 50HZ) Continuous
V
C
120
Calling Voltage (f = 50HZ)
5 Sec ON/10 Sec OFF
Supply Current
Operating Temperature
Storage and Junction Temperature
V
C(0N-OFF)
T
T
I
CC
ORR
STG
200
22
-20 ~ +70
-65 ~ +150
Absolute maximum ratings are those values beyond which permanent damage to the device may occur. These
are stress ratings only and functional operation of the device at or beyond them is not implied. Long exposure
to these conditions may affect device reliability.
DC ELECTRICAL CHARACTERISTICS (T
= 25°C)
a
Characteristic Symbol Test Conditions Min Typ Max Unit
Operating Voltage V
Current Consumption without Lode I
Activiation Voltage V
Activiation Voltage Range V
Sustaining Voltage V
Differential Resistance in off Condition R
Output Voltage Swing V
Short Circuit Current I
CC
CC
ON
ONR
SUS
D(OFF)
0(P-P)
SC
AC ELECTRICAL CHARACTERISTICS (T
= 25°C)
a
- - - 26 V
VS = 8.8 to 26V - 1.5 1.8 mA
- 12.2 - 13 V
RA = 1KΩ
8 - 10 V
- 8 - 8.8 V
- 6.4 - -
- -
VCC-3
VS = 26V - 35 - mA
Vrms
Vrms
mA
°C
°C
KΩ
- V
Characteristic Symbol Test Conditions Min Typ Max Unit
Output Frequencies (KA2418B)
Output Frequencies (KA2428)
f
Range f
H1
Sweep Frequency f
f
f
f
f
H1R
H1
H2
H1
H2
S
V
= 26V,R1 = 14KΩ
CC
VCC = OV
VCC = 6V
V
= 26V,R1 = 14KΩ
CC
VCC = OV
VCC = 6V
R1=27KΩ to 1.7KΩ
R1=14KΩ, C1=100nF
- 2300
1700
-
-
-
1900
1300
-
HZ
-
HZ
0.1 - 15 KH
- 10 - H
H
Z
H
Z
Z
Z